Midlatency median nerve evoked responses during recovery from propofol/sufentanil total intravenous anaesthesia ^Note

Abstract

Persistent changes of MnSSER waves > or =35 ms reflect impaired signal processing along the somatosensory pathway following propofol/sufentanil anaesthesia when the patients are responsive again. Further studies combining MnSSER recording with distinct neuro-psychological tests are needed to define the clinical relevance of these findings.

Cortical arousal in critically ill patients: an evoked response study

“…In contrast to the patients in the study of Sneyd et al, our patients did not require muscle relaxants, therefore a clinical sedation score including muscle responses could be used in parallel with the electrophysiological recordings. However, we included MnSSER, which have been shown to be another suitable parameter to monitor brain activity during anaesthesia [8]. In agreement with the previous study, the Nb latency decreased in our patients during physiotherapy and nursing care.…”

“…The study of Sneyd and co-workers [8] with a small number of patients was not set out as an outcome study, but a retrospective observation was that the patients who survived showed a greater reduction in Nb latency than those with fatal outcome. The authors explained the difference by the fact that the latter received more sedation.…”

“…However, the primary cortical complex N20P25 of the median nerve SER (MnS-SER) is known to change in relation to surgical stimulation [7]. Moreover, it has been demonstrated recently that anaesthetic-induced changes of MnSSER are reversed during recovery from anaesthesia in relation to the clinical awakening [8].…”

Recovery of memory after general anaesthesia: clinical findings and somatosensory evoked responses

“…4 5 We have shown, that MnSSER changes in relation to clinical awakening during recovery from general anaesthesia. 6 Theoretically, MnSSER could be used for monitoring during anaesthesia, if AER recording was not practical, for example as a result of hearing problems in patients.…”

Carotid Artery Surgery: Local Anaesthesia or Neuromonitoring

“…Es wird kontrovers diskutiert, welche SEP-Parameter und welche Schwellenwerte am besten geeignet ist, anhand derer die Indikation zur Anlage eines intraluminären Shunts intraoperativ gestellt werden kann [9,10] Grundsätzlich muss bei der Interpretation der SEP-Befunde berücksichtigt werden, dass auch Anästhetika zu Amplituden-und Latenzveränderungen der SEP führen, welche teilweise unter nozizeptiver Stimulation antagonisiert werden [11]. Ein SEP-Monitoring ist unter Gabe von intravenösen Anästhetika sehr gut durchführbar, da die Amplitude des N 20 P 25-Komplexes nur wenig reduziert wird [12]. Zu beachten ist, dass die Verabreichung von Lachgas vermieden werden sollte, da es zu einer starken Amplitudenreduktion führt [13].…”